Cysteine enhances in vivo natriuretic potency of ethacrynic acid in the rat.
Total renal blood flow, glomerular filtration rate, and renal excretory function were determined in anesthetized rats treated with intravenous infusion of ethacrynic acid, 0.36 mg.min-1.kg-1, alone or in combination with cysteine. Simultaneously, the corticomedullary electrolyte gradient was evaluated in vivo from measurement of tissue electrical admittance (reciprocal impedance). Renal hemodynamics was not altered by drug infusion. Sodium excretion increased 1.7-fold with ethacrynic acid alone and 5-fold after the addition of cysteine. Tissue electrolytes of inner medulla decreased much more in rats given ethacrynic acid plus cysteine. We conclude that the addition of cysteine to intravenous infusion of ethacrynic acid greatly enhances its in vivo natriuretic potency in the rat.
Kompanowska-Jezierska
E
E
Department of Applied Physiology, Medical Research Center of the Polish Academy of Sciences, Warsaw.
Dobrowolski
L
L
Sadowski
J
J
D000818:Animals; D003545:Cysteine / Q000494:pharmacology*; D004976:Ethacrynic Acid / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000502:physiology; D007679:Kidney Medulla / Q000187:drug effects / Q000502:physiology; D008138:Loop of Henle / Q000187:drug effects / Q000502:physiology; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
D003545:Cysteine; D004976:Ethacrynic Acid